deac/osd-contiki
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity
osd-contiki/cpu/cc2538/dev/spi.c
Benoît Thébaudeau 8b57670121 cc2538: spi: Add support for dynamic clock frequency 
This changes makes it possible to change the SPI clock frequency at
runtime.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
2016-11-27 22:50:43 +01:00

363 lines
11 KiB
C
Raw Blame History

/*
* Copyright (c) 2013, University of Michigan.
*
* Copyright (c) 2015, Weptech elektronik GmbH
* Author: Ulf Knoblich, ulf.knoblich@weptech.de
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/**
* \addtogroup cc2538-spi
* @{
*
* \file
* Implementation of the cc2538 SPI peripheral driver
*/
#include "contiki.h"
#include "reg.h"
#include "spi-arch.h"
#include "sys/cc.h"
#include "dev/ioc.h"
#include "dev/sys-ctrl.h"
#include "dev/spi.h"
#include "dev/ssi.h"
#include "dev/gpio.h"
/*---------------------------------------------------------------------------*/
/* Check port / pin settings for SPI0 and provide default values for spi_cfg */
#ifndef SPI0_CLK_PORT
#define SPI0_CLK_PORT (-1)
#endif
#ifndef SPI0_CLK_PIN
#define SPI0_CLK_PIN (-1)
#endif
#if SPI0_CLK_PORT >= 0 && SPI0_CLK_PIN < 0 || \
SPI0_CLK_PORT < 0 && SPI0_CLK_PIN >= 0
#error Both SPI0_CLK_PORT and SPI0_CLK_PIN must be valid or invalid
#endif
#ifndef SPI0_TX_PORT
#define SPI0_TX_PORT (-1)
#endif
#ifndef SPI0_TX_PIN
#define SPI0_TX_PIN (-1)
#endif
#if SPI0_TX_PORT >= 0 && SPI0_TX_PIN < 0 || \
SPI0_TX_PORT < 0 && SPI0_TX_PIN >= 0
#error Both SPI0_TX_PORT and SPI0_TX_PIN must be valid or invalid
#endif
#ifndef SPI0_RX_PORT
#define SPI0_RX_PORT (-1)
#endif
#ifndef SPI0_RX_PIN
#define SPI0_RX_PIN (-1)
#endif
#if SPI0_RX_PORT >= 0 && SPI0_RX_PIN < 0 || \
SPI0_RX_PORT < 0 && SPI0_RX_PIN >= 0
#error Both SPI0_RX_PORT and SPI0_RX_PIN must be valid or invalid
#endif
/* Here we check that either all or none of the ports are defined. As
we did already check that both ports + pins are either defined or
not for every pin, this means that we can check for an incomplete
configuration by only looking at the port defines */
/* If some SPI0 pads are valid */
#if SPI0_CLK_PORT >= 0 || SPI0_TX_PORT >= 0 || SPI0_RX_PORT >= 0
/* but not all */
#if SPI0_CLK_PORT < 0 || SPI0_TX_PORT < 0 || SPI0_RX_PORT < 0
#error Some SPI0 pad definitions are invalid
#endif
#define SPI0_PADS_VALID
#endif
/*---------------------------------------------------------------------------*/
/* Check port / pin settings for SPI1 and provide default values for spi_cfg */
#ifndef SPI1_CLK_PORT
#define SPI1_CLK_PORT (-1)
#endif
#ifndef SPI1_CLK_PIN
#define SPI1_CLK_PIN (-1)
#endif
#if SPI1_CLK_PORT >= 0 && SPI1_CLK_PIN < 0 || \
SPI1_CLK_PORT < 0 && SPI1_CLK_PIN >= 0
#error Both SPI1_CLK_PORT and SPI1_CLK_PIN must be valid or invalid
#endif
#ifndef SPI1_TX_PORT
#define SPI1_TX_PORT (-1)
#endif
#ifndef SPI1_TX_PIN
#define SPI1_TX_PIN (-1)
#endif
#if SPI1_TX_PORT >= 0 && SPI1_TX_PIN < 0 || \
SPI1_TX_PORT < 0 && SPI1_TX_PIN >= 0
#error Both SPI1_TX_PORT and SPI1_TX_PIN must be valid or invalid
#endif
#ifndef SPI1_RX_PORT
#define SPI1_RX_PORT (-1)
#endif
#ifndef SPI1_RX_PIN
#define SPI1_RX_PIN (-1)
#endif
#if SPI1_RX_PORT >= 0 && SPI1_RX_PIN < 0 || \
SPI1_RX_PORT < 0 && SPI1_RX_PIN >= 0
#error Both SPI1_RX_PORT and SPI1_RX_PIN must be valid or invalid
#endif
/* If some SPI1 pads are valid */
#if SPI1_CLK_PORT >= 0 || SPI1_TX_PORT >= 0 || SPI1_RX_PORT >= 0
/* but not all */
#if SPI1_CLK_PORT < 0 || SPI1_TX_PORT < 0 || SPI1_RX_PORT < 0
#error Some SPI1 pad definitions are invalid
#endif
#define SPI1_PADS_VALID
#endif
#ifdef SPI_DEFAULT_INSTANCE
#if SPI_DEFAULT_INSTANCE == 0
#ifndef SPI0_PADS_VALID
#error SPI_DEFAULT_INSTANCE is set to SPI0, but its pads are not valid
#endif
#elif SPI_DEFAULT_INSTANCE == 1
#ifndef SPI1_PADS_VALID
#error SPI_DEFAULT_INSTANCE is set to SPI1, but its pads are not valid
#endif
#endif
#endif
#if (SPI0_CPRS_CPSDVSR & 1) == 1 || SPI0_CPRS_CPSDVSR < 2 || SPI0_CPRS_CPSDVSR > 254
#error SPI0_CPRS_CPSDVSR must be an even number between 2 and 254
#endif
#if (SPI1_CPRS_CPSDVSR & 1) == 1 || SPI1_CPRS_CPSDVSR < 2 || SPI1_CPRS_CPSDVSR > 254
#error SPI1_CPRS_CPSDVSR must be an even number between 2 and 254
#endif
/*---------------------------------------------------------------------------*/
/*
* Clock source from which the baud clock is determined for the SSI, according
* to SSI_CC.CS.
*/
#define SSI_SYS_CLOCK SYS_CTRL_SYS_CLOCK
/*---------------------------------------------------------------------------*/
typedef struct {
int8_t port;
int8_t pin;
} spi_pad_t;
typedef struct {
uint32_t base;
uint32_t ioc_ssirxd_ssi;
uint32_t ioc_pxx_sel_ssi_clkout;
uint32_t ioc_pxx_sel_ssi_txd;
uint8_t ssi_cprs_cpsdvsr;
spi_pad_t clk;
spi_pad_t tx;
spi_pad_t rx;
} spi_regs_t;
/*---------------------------------------------------------------------------*/
static const spi_regs_t spi_regs[SSI_INSTANCE_COUNT] = {
{
.base = SSI0_BASE,
.ioc_ssirxd_ssi = IOC_SSIRXD_SSI0,
.ioc_pxx_sel_ssi_clkout = IOC_PXX_SEL_SSI0_CLKOUT,
.ioc_pxx_sel_ssi_txd = IOC_PXX_SEL_SSI0_TXD,
.ssi_cprs_cpsdvsr = SPI0_CPRS_CPSDVSR,
.clk = { SPI0_CLK_PORT, SPI0_CLK_PIN },
.tx = { SPI0_TX_PORT, SPI0_TX_PIN },
.rx = { SPI0_RX_PORT, SPI0_RX_PIN }
}, {
.base = SSI1_BASE,
.ioc_ssirxd_ssi = IOC_SSIRXD_SSI1,
.ioc_pxx_sel_ssi_clkout = IOC_PXX_SEL_SSI1_CLKOUT,
.ioc_pxx_sel_ssi_txd = IOC_PXX_SEL_SSI1_TXD,
.ssi_cprs_cpsdvsr = SPI1_CPRS_CPSDVSR,
.clk = { SPI1_CLK_PORT, SPI1_CLK_PIN },
.tx = { SPI1_TX_PORT, SPI1_TX_PIN },
.rx = { SPI1_RX_PORT, SPI1_RX_PIN }
}
};
/*---------------------------------------------------------------------------*/
/* Deprecated function call provided for compatibility reasons */
#ifdef SPI_DEFAULT_INSTANCE
void
spi_init(void)
{
spix_init(SPI_DEFAULT_INSTANCE);
}
#endif /* #ifdef SPI_DEFAULT_INSTANCE */
/*---------------------------------------------------------------------------*/
void
spix_init(uint8_t spi)
{
const spi_regs_t *regs;
if(spi >= SSI_INSTANCE_COUNT) {
return;
}
regs = &spi_regs[spi];
if(regs->clk.port < 0) {
/* Port / pin configuration invalid. We checked for completeness
above. If clk.port is < 0, this means that all other defines are
< 0 as well */
return;
}
spix_enable(spi);
/* Start by disabling the peripheral before configuring it */
REG(regs->base + SSI_CR1) = 0;
/* Set the system clock as the SSI clock */
REG(regs->base + SSI_CC) = 0;
/* Set the mux correctly to connect the SSI pins to the correct GPIO pins */
ioc_set_sel(regs->clk.port,
regs->clk.pin,
regs->ioc_pxx_sel_ssi_clkout);
ioc_set_sel(regs->tx.port,
regs->tx.pin,
regs->ioc_pxx_sel_ssi_txd);
REG(regs->ioc_ssirxd_ssi) = (regs->rx.port * 8) + regs->rx.pin;
/* Put all the SSI gpios into peripheral mode */
GPIO_PERIPHERAL_CONTROL(GPIO_PORT_TO_BASE(regs->clk.port),
GPIO_PIN_MASK(regs->clk.pin));
GPIO_PERIPHERAL_CONTROL(GPIO_PORT_TO_BASE(regs->tx.port),
GPIO_PIN_MASK(regs->tx.pin));
GPIO_PERIPHERAL_CONTROL(GPIO_PORT_TO_BASE(regs->rx.port),
GPIO_PIN_MASK(regs->rx.pin));
/* Disable any pull ups or the like */
ioc_set_over(regs->clk.port, regs->clk.pin, IOC_OVERRIDE_DIS);
ioc_set_over(regs->tx.port, regs->tx.pin, IOC_OVERRIDE_DIS);
ioc_set_over(regs->rx.port, regs->rx.pin, IOC_OVERRIDE_DIS);
/* Configure the clock */
REG(regs->base + SSI_CPSR) = regs->ssi_cprs_cpsdvsr;
/*
* Configure the default SPI options.
* mode: Motorola frame format
* clock: High when idle
* data: Valid on rising edges of the clock
* bits: 8 byte data
*/
REG(regs->base + SSI_CR0) = SSI_CR0_SPH | SSI_CR0_SPO | (0x07);
/* Enable the SSI */
REG(regs->base + SSI_CR1) |= SSI_CR1_SSE;
}
/*---------------------------------------------------------------------------*/
void
spix_enable(uint8_t spi)
{
if(spi >= SSI_INSTANCE_COUNT) {
return;
}
REG(SYS_CTRL_RCGCSSI) |= (1 << spi);
}
/*---------------------------------------------------------------------------*/
void
spix_disable(uint8_t spi)
{
if(spi >= SSI_INSTANCE_COUNT) {
return;
}
REG(SYS_CTRL_RCGCSSI) &= ~(1 << spi);
}
/*---------------------------------------------------------------------------*/
void
spix_set_mode(uint8_t spi,
uint32_t frame_format,
uint32_t clock_polarity,
uint32_t clock_phase,
uint32_t data_size)
{
const spi_regs_t *regs;
if(spi >= SSI_INSTANCE_COUNT) {
return;
}
regs = &spi_regs[spi];
/* Disable the SSI peripheral to configure it */
REG(regs->base + SSI_CR1) = 0;
/* Configure the SSI options */
REG(regs->base + SSI_CR0) = clock_phase |
clock_polarity |
frame_format |
(data_size - 1);
/* Re-enable the SSI */
REG(regs->base + SSI_CR1) |= SSI_CR1_SSE;
}
/*---------------------------------------------------------------------------*/
void
spix_set_clock_freq(uint8_t spi, uint32_t freq)
{
const spi_regs_t *regs;
uint64_t div;
uint32_t scr;
if(spi >= SSI_INSTANCE_COUNT) {
return;
}
regs = &spi_regs[spi];
/* Disable the SSI peripheral to configure it */
REG(regs->base + SSI_CR1) = 0;
/* Configure the SSI serial clock rate */
if(!freq) {
scr = 255;
} else {
div = (uint64_t)regs->ssi_cprs_cpsdvsr * freq;
scr = (SSI_SYS_CLOCK + div - 1) / div;
scr = MIN(MAX(scr, 1), 256) - 1;
}
REG(regs->base + SSI_CR0) = (REG(regs->base + SSI_CR0) & ~SSI_CR0_SCR_M) |
scr << SSI_CR0_SCR_S;
/* Re-enable the SSI */
REG(regs->base + SSI_CR1) |= SSI_CR1_SSE;
}
/*---------------------------------------------------------------------------*/
void
spix_cs_init(uint8_t port, uint8_t pin)
{
GPIO_SOFTWARE_CONTROL(GPIO_PORT_TO_BASE(port),
GPIO_PIN_MASK(pin));
ioc_set_over(port, pin, IOC_OVERRIDE_DIS);
GPIO_SET_OUTPUT(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin));
GPIO_SET_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin));
}
/** @} */
Reference in a new issue View git blame Copy permalink